RECENT ADVANCES IN THE CONSTRUCTION OF BACTERIAL GENOTOXICITY ASSAYS

Bacterial mutagenicity assays have been widely used in genotoxicology research for two decades. We discuss the development of such assays, e specially the Ames test, with particular attention to strain engineeri ng. Genes encoding enzymes of mutagen bioactivation, including N-acety ltransferase, nitroreductase, and cytochrome P450, have been introduce d into tester strains. The processing of DNA damage by the bacterial s trains has also been modified in several ways, so as to enhance mutage nesis. These efforts have greatly increased the sensitivity of mutatio n assays and have illuminated the molecular mechanisms of mutagenesis. We also discuss the relationship between bacterial assays and in vivo mutation assays which use transgenic rodents.